Lawn mower sharpener



Aug. 25, 1942. w LAW 2,293,837

LAWN Mo HARPENER //1/ 1/5/1/ roe A /,f1////VE WHW.

Patented Aug. 25, 1942 Unirse sra'ra par A NICE 2 Claims.

My invention relates to a lawn mower sharpening device and has for yitsprincipal object, to provide a relatively simple and inexpensivestructure including a conventional flat face le and a pair of membersthat are adjust'ably mounted on said le, thereby providing a practicaland eliicient tool Vthat may be conveniently used for rapidly sharpeningthe edges of the curved blades of a lawn mower land likewise forsharpening the straight edge of the cutter bar with which the bladescooperate during operation of the lawn mower.

A further object of my invention is, to provide in a lawn mowerSharpener of the character referred to a one-piece member having aportion Y that provides a convenient handle for grasping one end of theile and another portion shaped so as to provide a runner that slideslengthwise upon the tie bar or connecting rod between the sides of thelawn mower, thus guiding the file during blade sharpening operations.

A further object of my invention is, to provide in a. lawn mowerSharpener a one-piece member that is removably and adjustably applied tothe le and which serves as a guide for the edges of the curved bladesand Ialso as a guide for the cutter bar during sharpening operations.

With the foregoing and other objects in View, my invention consists incertain novel features of construction and arrangement of parts thatwill be hereinafter more fully described and claimed and illustrated inthe accompanying drawing in which:

Fig. 1 is a top plan view of a lawn mower sharpener constructed inaccordance with my invention.

Fig. 2 is a side elevational View of the Sharpener and showing the samein position upon the transverse tie rodand one of th'e curved blades ofthe lawn mower.

Fig. 3 is a View looking against the under side of the Sharpener.

Fig. 4 is an enlarged cross section taken on the line 4 4 of Fig. 1.

Fig. 5 is an enlarged detail section taken on the line 5 5 of Fig. 1.

Referring by numerals to the accompanying drawing which illustrates apreferred embodiment of my invention, IU designates a le of the typehaving oppositely disposed flat faces on which are formed conventionalfile teeth and projecting from one end of the le body is a taperedhandle II.

The member that provides a combined handle and guide for the device, isformed from a single piece of sheet metal, a portion of which is bent toform a ilat tube I2 which is approximately three or four inches long inorder to be conveniently gripped in the hand of the user, and the crosssectional dimensions of the opening through this tube are slightlylarger than the cross sectional dimensions of th'e rear end of the bodyof the ile It. Thus the tube may conveniently receive a portion of therear end ofthe le body, .together with the handle I I that projectstherefrom.

The upper wall of the tube I2 is provided withva longitudinally disposedslot I3.

Screw seated in the central portion of the bottom wall of the tube lis aset screw I4 which Wh'en tightened against the handle -I I of the filefirmly clamps the .tube thereto.

Projecting from the inner end of the bottom wall of the tube I2 is anarm I5, the terminal portion of which is bent to form a substantiallyinverted U-shaped member I 6 which wh'en the Sharpener is in use engagesover the transverse rod R that functions as a tie rod between the sidemembers of thc lawn mower frame and as a result of this construction,the Sharpener is guided so as to' traverse a definite transverse pathwhile being reciprocated during sharpening operations.

Removably and adjustably mounted upon the body I0 of the le is a memberthat engages the curved blades or the cutter bar of the lawn mower whilethe same are being sharpened and this member, which is formed fromsuitable sheet metal, comprises a substantially rectangular top plateII, end plates I8, and bottom plates I9, which latter are approximatelytriangular in shape as illustrated in Fig. 3.

The end walls I8 are provided with slots 20 for the reception of thebody of the file and passing through the central portion of top plateI'I is a set screw 2l which when tightened bears against the uppersurface of the file to rmly secure thev guiding member thereto.

From the lower ends of the end walls I8 of this guiding member, thetriangular plates I9 extend downwardly at slight angles relative to theplane occupied by the top plate I'I and the at surfaces of the le towhich the guiding member is attached and the apices of th'e triangularplates are cut away to form short straight parallel edges 20a spacedapart a sufficient distance to receive the curved blades of the lawnmower adjacent their edges (see Figs. 2 and 5) When the device is usedfor sharpening the curved blades of lawn mowers, the handle member I2and blade guiding member 'are applied to the file Ill as illustrated inFigs. 1 and 2 and after being properly adjusted thereon, they aresecured to the le by tightening th'e screws I4 and 2l. Inverted U-shapedmember I6 is positioned over the cross bar or tie rod R and the deviceis manipulated so that the edge of the curved blade to be sharpened ispositioned between the edges 20a of the triangular members I9.

The sharpening device is now reciprocated transversely of the lawn mowerwith the rod I3 serving to guide the sharpening device during such'movements and suiiicient downward pressure is exerted on the end of thele body opposite the end that is provided with the handle, so as tocause the teeth on the under surface of the file to engage and abradethe cutting edge of the blade so as to effectively sharpen same.

During this sharpening action, it will be understood that the bladeth'at is being sharpened will swing or rotate slightly due to itslongitudinal curvature, but such movement does not aiect the sharpeningof the cutting edge of said blade.

To sharpen the edge of the cutter bar of the lawn mower against whichthe sharp edges of the blades engage, the guide member comprising theparts I1, I8, and I9, is positioned and adjusted upon the body of the leso that the outer face of one of the end walls I8 engages against theside face of the cutter bar adjacent its cutting edge and thus the iilewhen reciprocated abrades and consequently sharpens the cutting edge ofsaid cutter bar.

Thus it will be seen that I have provided a lawn mower Sharpener that isrelatively simple in construction, inexpensive of manufacture, and veryeffective in performing the functions for which it is intended.

It will be understood that minor changes in th'e size, form andconstruction of the various parts of my improved lawn mower Sharpener,may be made and substituted for those herein shown and described,without departing from the spirit of my invention, the scope of which isset forth in the appended claims.

I claim as my invention:

1. In a lawn mower Sharpener, the combination with a rile, of a flattube detachably and adjustably applied to one end of said file, thelength of which tube is such as to provide a handle for gripping andmanipulating the file, a set screw seated in one of the walls of saidtubular handle for clamping the same to the file, an arm projectinginwardly from the inner end of said tubular handle, the inner portion ofwhich arm terminates in an inverted U-shaped member that is adapted toengage the transverse tie rod of the lawn mower on which the Sharpeneris used and a combined blade and cutter bar guide detachably andadjustably mounted on the body of the iile.

2. In a lawn mower sharpening device, the combination with a iiat facedfile, of a at tube removably positioned upon one end of said iile, thelength of which tube is such as to provide a handle for gripping andmanipulating said ille, means carried by said tube for clamping the sameto said file in diierently adjusted positions, an arm projecting fromthe inner end of said tubular handle, an inverted U-shaped member formedon said arm for engaging the transverse tie rod of a lawn mower 'and acombined lawn mower blade and cutter bail guide removably and adjustablymounted on said file.

IRVINE W. LAW.

